The present disclosure relates to computing systems, and, in particular, to computing systems providing data backup and related methods.
CA ARCserve Replication and High Availability (CA ARCserve RHA) and CA ARCserve D2D are designed to work together to allow a user to replicate their CA ARCserve D2D (Disk-to-Disk) backups from a local master server (also referred to as a protected server) to a replica server at an offsite location for additional security and recoverability. These CA ARCserve D2D backups can then be restored from either the local backup at the protected server or from the remote replica copy at the replica server. CA ARCserve RHA is discussed, for example, in “CA ARCserve RHA and CA ARCserve D2d, Integrated Solutions Guide, r16,” copyright 2011, the disclosure of which is hereby incorporated herein in its entirety by reference.
Regarding CA ARCserve RHA, the data on the master and replica servers may need to be synchronized before beginning the replication phase. In order to synchronize data using a file-based method, files in the master server root directory and the replica server root directory may have to be traversed and sorted by file name, respectively, to generate file directory snapshots using VSS (Volume Shadow Copy Service) snapshot. Then, the two directory snapshot files may be compared to identify which file or files should be sent to the replica server.
If there are hard link files among the files with the small file size in the protected master server directory, the hard link files may be processed as normal files.
A characteristic of hard link files is that multiple hard link files may actually point to the same physical data file. Assuming that there may be millions of files, with half of the files being hard link files, a conventional replication method may send duplicated file data to the replica server without knowledge of multiple related hard link files resulting in redundant IO (input/output) operations to synchronize the data. Currently, most file systems on Windows and Unix based platforms may support hard link files. Moreover, current Windows operating systems have used hard link files for fast feature installations. When a hard link file is created or changed, the snapshot may not reflect the latest changes. Accordingly, more efficient ways to synchronize hard link files may be desired to reduce multiple transmissions of duplicated data files to the replica server and/or to improve synchronization speeds while reflecting the latest changes at the replica server.